What is electrode potential?
electrode potential is a combined potential of two electrodes that are subject to reactions in the cell. Usually measured in volts, it may vary from the substances from which the electrodes are made. Hydrogen is often considered a standard with the potential of zero volts, from which the reactions of other elements are compared. Electrochemical processes can be foreseen by understanding the electrode potential of the material, as well as the chances of corroding in specific circumstances. This potential is also called the electromotic force (EMF), in general it is measured using a galvanic cell, which consists of two chambers, each of which has an electrode and connected by a piece of paper called a salty bridge.
The electrical current of the cell is usually measured by a voltmeter. There may be no current; The difference in the potential between electrodes in this case is usually the same as the EMF of the entire cell. EMF is generally measured at 77 ° F (about 25 ° C) and typical atmospheric pressure on the sea level. Such conditions are used to assess the standard electrode potential in conFigure of two cells. The hydrogen electrode is usually on one side of this layout, while the potential on the other side is usually determined by an experiment.
Once this standard value is derived, then it is possible to predict how the substance will react. Usually, the higher the negative value of the potential, the more likely the element is dissolved in the solution. No reaction is often observed in non -active metals. These are usually located at the bottom of the standard table potential table, which identifies EMF different types of elements. The elements are generally arranged in the order of their tendency to react, so the elements are higher because they react more often than negatively charged substances.
Standard conditions are not adostulative LWAYS, so the calculation called Nernst equation can be used to determine the potential of electrodes. It is created for temperature, gas constant, how many particles called electrons are transmitted and KOncentration of ions. While hydrogen is a standard reference, elements often used for electrodes include zinc and copper, iron, aluminum or calcium.
Electrode potential of each of these elements is used to calculate the voltage of the galvanic cell. A separate calculation of atomic half reactions is sometimes used to derive EMF. Therefore, the process of determining the potential of electrodes may require an understanding of scientific principles and mathematics.